Voicemail storage in traditional communication and collaboration systems is often provided by a dedicated voicemail server. Such servers serve many users and, as a result, are provided with large amounts of non-volatile memory and signal processing equipment. As such, these servers are expensive and their expense leads to issues of affordability in the scaling of communication and collaboration systems, for example in installations in the SOHO (small office-home office), small business and large enterprise branch markets. Several issues are related to the expense of such systems.
One factor relating to the costliness of such systems is a need to provide a sufficient degree of resiliency in the storage of voicemails. For example, for users who are affected by Sarbanes-Oxley and/or by litigation, loss of voicemails could have serious legal consequences. Traditional methods of resiliency for voicemails require duplicated storage possibly on separate servers, which leads to increased use of resources and expense.
Another major issue to some systems is voicemail SPAM. Large amounts of SPAM can be sent for a trivial cost to the sender but with large costs in storage and handling being borne by the receiver. This is especially true for voice and multimedia SPAM because of the large size of the files that need to be stored.
Several solutions have been used to address the issue of the scalability for voicemail systems to small installation sizes. By far the most commonly used is the provision of a network (possibly hosted) server that can serve a large number of installations. The cost of an extra server is undesirable for small installations. As well, a hosted server can be unattractive due to the potential of high prices, low reliability and indifferent customer service.
Voicemail can also be stored at the receiving telephone device, however, such local storage has several disadvantages. For example, memory is not a trivial expense and commercially, end user devices are cost sensitive. Further some end points can receive far more voicemail than others, depending on the amount of memory provided. Hence, for economy, each telephone device will have to be sized for the worst case unless special options or devices are offered for heavy voicemail users. Commercially this adds cost to a product line.